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Finding the Fourth Proportional to 90.40, 125.04 and 85.36

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Solution

The fourth proportional to 90.40, 125.04 and 85.36 is: 118.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.40 : 125.04 = 85.36 : x
  2. Step 2: Convert to fraction form
    90.40/125.04 = 85.36/x
  3. Step 3: Cross multiply
    90.40x = 125.04 × 85.36
  4. Step 4: Simplify right side
    90.40x = 10,673.41
  5. Step 5: Solve for x
    x = 10,673.41/90.40
  6. Step 6: Final answer
    x = 118.07

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.